Combined Application of Bacterial Predation and Violacein to Kill Polymicrobial Pathogenic Communities. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Im, Hansol; Choi, Seong; Son, Sangmo; Mitchell, Robert
• Is Part Of: Scientific reports. Volume 7:Issue 1(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-12
• Subjects: Natural history -- Research -- Periodicals; Biology -- Research -- Periodicals; Physical sciences -- Research -- Periodicals; Earth sciences -- Research -- Periodicals; Environmental sciences -- Research -- Periodicals; 502.85
• DOI: 10.1038/s41598-017-14567-7
• Languages: English
• ISSNs: 2045-2322

Abstract

Abstract Violacein is a bisindole antibiotic that is effective against Gram-positive bacteria while the bacterial predator, Bdellovibrio bacteriovorus HD100, predates on Gram-negative strains. In this study, we evaluated the use of both together against multidrug resistant pathogens. The two antibacterial agents did not antagonize the activity of the other. For example, treatment ofStaphylococcus aureus with violacein reduced its viability by more than 2, 000-fold with or withoutB. bacteriovorus addition. Likewise, predation ofAcinetobacter baumannii reduced the viability of this pathogen by more than 13, 000-fold, regardless if violacein was present or not. When used individually against mixed bacterial cultures containing both Gram-positive and Gram-negative strains, violacein andB. bacteriovorus HD100 were effective against only their respective strains. The combined application of both violacein andB. bacteriovorus HD100, however, reduced the total pathogen numbers by as much as 84, 500-fold. Their combined effectiveness was also demonstrated using a 4-species culture containingS. aureus, A. baumannii, Bacillus cereus andKlebsiella pneumoniae . When used alone, violacein and bacterial predation reduced the total population by only 19% and 68%, respectively. In conjunction with each other, the pathogen viability was reduced by 2, 965-fold (99.98%), illustrating the prospective use of these two antimicrobials together against mixed species populations.